PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- La Paz M.N., Fonseca V.U., Campos D.B., Artoni L.P., Sousa L.M.M.C. & Papa P.C. 2007. [In vitro progesterone production from bovine corpus luteum throughout gestation.] Produção de progesterona in vitro pelas células do corpo lúteo bovino ao longo da gestação. Pesquisa Veterinária Brasileira 27(9):370376. Setor de Anatomia, Departamento de Cirurgia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques Paiva, 87, SP 05508-270, Brazil. E-mail: ppapa@usp.br The aim was to test the hypothesis that cultivated bovine luteal cells from three different thirds of pregnancy behave the same way as in vivo luteal cells relative to P4 production. Corpus luteum samples from days 90 (n=3), 150 (n=3) and 210 (n=3) of pregnancy were obtained at a local slaughterhouse. Under aseptic conditions cells were mechanically dispersed and cultivated in a 96 wells-plate. After 24 hours of culture, cells were washed and the precursor pregnenolone was added. Experiments were conducted eight times for each studied time period (24, 48 and 96 h) and three times for each gestational age. Culture medium and cells were collected after 24, 48 and 96 hours of precursor addition and kept frozen at -20oC until processing. Progesterone was measured by RIA and protein content by Lowry’s method. Results were statistically analyzed and considered different when p <0.05. A higher P4 production was observed on day 90 of gestation (35.277±0.075), then this production was decreased at day 150 (28.820±0.231) and increased again at day 210 (32.777±0.099). After 24 hours of culture, luteal cells P4 production reached maximum values in the group of 90 days (2.912±0.047) when compared to 150 (2.669±0.137) and 210 days (2.741±0.088). At 48 and 96 hours of culture, bovine luteal cells from day 90 of gestation produced more P4 than cells from day 210 (2.934±0.029 and 2.976±0.121 respectively x 2.760±0.059 and 2.695±0.149, respectively; p<0.05), which in turn, produced more P4 than cells from day 150 (2.334±0.084 for 48 h and 2.205±0.136 for 96 h). Luteal cells from day 150 of gestation presented a decreasing P4 production throughout the 96 hours of culture. These differences could be explained by differential gene expression of enzymes and/or factors belonging to the esteroidogenic cascade in accordance to the gestational period. The established luteal cell culture model could be used for further functional studies once P4 secretion pattern in vitro resembled what occurs in vivo.

• Corpus luteum gestation progesterone cell culture

Abstract in Portuguese:

ABSTRACT.- La Paz M.N., Fonseca V.U., Campos D.B., Artoni L.P., Sousa L.M.M.C. & Papa P.C. 2007. [In vitro progesterone production from bovine corpus luteum throughout gestation.] Produção de progesterona in vitro pelas células do corpo lúteo bovino ao longo da gestação. Pesquisa Veterinária Brasileira 27(9):370376. Setor de Anatomia, Departamento de Cirurgia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques Paiva, 87, SP 05508-270, Brazil. E-mail: ppapa@usp.br The aim was to test the hypothesis that cultivated bovine luteal cells from three different thirds of pregnancy behave the same way as in vivo luteal cells relative to P4 production. Corpus luteum samples from days 90 (n=3), 150 (n=3) and 210 (n=3) of pregnancy were obtained at a local slaughterhouse. Under aseptic conditions cells were mechanically dispersed and cultivated in a 96 wells-plate. After 24 hours of culture, cells were washed and the precursor pregnenolone was added. Experiments were conducted eight times for each studied time period (24, 48 and 96 h) and three times for each gestational age. Culture medium and cells were collected after 24, 48 and 96 hours of precursor addition and kept frozen at -20oC until processing. Progesterone was measured by RIA and protein content by Lowry’s method. Results were statistically analyzed and considered different when p <0.05. A higher P4 production was observed on day 90 of gestation (35.277±0.075), then this production was decreased at day 150 (28.820±0.231) and increased again at day 210 (32.777±0.099). After 24 hours of culture, luteal cells P4 production reached maximum values in the group of 90 days (2.912±0.047) when compared to 150 (2.669±0.137) and 210 days (2.741±0.088). At 48 and 96 hours of culture, bovine luteal cells from day 90 of gestation produced more P4 than cells from day 210 (2.934±0.029 and 2.976±0.121 respectively x 2.760±0.059 and 2.695±0.149, respectively; p<0.05), which in turn, produced more P4 than cells from day 150 (2.334±0.084 for 48 h and 2.205±0.136 for 96 h). Luteal cells from day 150 of gestation presented a decreasing P4 production throughout the 96 hours of culture. These differences could be explained by differential gene expression of enzymes and/or factors belonging to the esteroidogenic cascade in accordance to the gestational period. The established luteal cell culture model could be used for further functional studies once P4 secretion pattern in vitro resembled what occurs in vivo.

Abstract in English:

Antibiotic and chemotherapeutic drug sensitivity of 951 cultures of Staphylococcus sp., 590 cultures of Streptococcus sp. and 550 cultures of Corynebacterium sp., isolates of bovine mastites were studied. Staphylococcus sp. showed the highest levels of sensitivity (75-90%) to Cephalothin, Nitrofurantoin Vancomycin and Novobiocion: Complete resistance was seen against Phosphomycin, Polymyxin B, Colestin Sulphate and Rifamycin. In relation to Streptococcus sp., the most effective antibiotics were Chloramphenicol, Novobiocin and Vancomycin (72-77%). High levels of resistance (90-100%) were seen with Rifamycin, Streptomycin, Colestin Sulfate, Sulfomethoxazole, Phosphomycin and Polymyxin B. As for the cultures of Corynebacterium sp., the greatest sensitivity was seen with Cephalosporin (100%), followed by Erythromycin, Chloramphenicol, Gentamycin, Kanamycin, Tetracycline, Carbenicillin and Tobramycin (80-97%). None of the samples of Corynebacterium sp. studied showed complete resistance to any of the drugs tested.

• in vitro sensitivity antibiotics chemotherapeutic drugs mastitis cattle

Abstract in Portuguese:

Estudou-se in vitro a sensibilidade a antimicrobianos de 951 amostras de bactérias do gênero Staphylococcus, 590 amostras do gênero Streptococcus e 550 do gênero Corynebacterium, isoladas de mastites bovinas. Obtiveram-se os seguintes resultados em relação às bactérias do gênero Staphylococçus: os maiores índices de sensibilidade (75 a 90%) foram os observados frente à cefalosporina, nitrofurantoína, vancomicina e novobiocina. Observou-se 100% de resistência frente à fosfomicina, polimixina B, sulfato de colistina e rifamicina. Em relação a Streptococcus sp., os antimicrobianos mais efetivos foram cloranfenicol, novobiocina e vancomicina (sensibilidade de 72 a 77%). Altos índices de resistência (90 a 100%) foram observados frente à rifamicina, estreptomicina, sulfato de colistina, sulfametoxazol, fosfomicina e polimixina B. Quanto às amostras de Corynebacterium sp., a maior sensibilidade foi observada frente à cefalosporina (100%), seguida da eritromicina, cloranfenicol, gentamicina, canamicina, tetraciclina, carbenicilina e tobramicina (97 a 80%). Não foi observada resistência máxima (100%) aos antimicrobianos nas amostras de Corynebacterium sp. estudadas.

• Sensibilidade in vitro antimicrobianos mastite bovinos